Although statistics indicate that vehicles equipped with air-bags have enhanced passenger safety, under certain conditions air-bags have been identified as the primary source of passenger injuries and have even been cited in several cases as causing death. Deaths have been directly attributed to air-bags predominantly in low-speed accidents. However, despite the difficulty in nailing down a single cause of death in high-speed accidents, it is likely that air-bags have also played a significant role in deaths resulting from high-speed accidents.
A large number of these injuries have involved shorter drivers--more specifically, drivers 5' 0" or less in height--who adjust the seat position so that a distance between the air-bag and the driver are reduced below a safe clearance. Of course, it should be understood that drivers taller than 5'0" may also position themselves within the minimum safe clearance and this positioning is dangerous regardless of the height of the driver. In known systems, as all of the adjustment for drivers of various sizes is generally done through seat movement, shorter drivers are often positioned much closer to the steering wheel (and the air-bag contained therein) than are taller drivers. As indicated above, this often results in shorter drivers (e.g., 5' 0" or less in height), along with taller drivers who chose to sit close to the steering wheel, being positioned within a predetermined safe clearance. Depending on the air-bag system used, the safe clearance may vary. However, a 10" clearance between the driver and the air-bag is usually sufficient to eliminate the negative effects of air-bag systems.
Conventional seats generally allow adjustment of the driver's seat between a rearward-most position and a forward-most position separated by a distance sufficient to accommodate the range of leg lengths in the adult population, e.g., approximately 8". These systems primarily address differences in leg length as differences in arm and torso length among the population are less substantial.
Thus, in order to operate the pedals in prior systems, shorter adults were forced to move the seat forward, often to the forward-most position while a portion of taller adults also chose to move the seat beyond the safe clearance. This causes a corresponding distance closure between the drivers chest and head and the steering wheel in which the air-bag is often located. Thus, when the seat is in the forward-most position, a driver will be separated from the steering wheel by a distance less than the required minimum safe clearance.
This problem has been addressed by systems which determine when the driver is positioned closer than the minimum safe clearance and then adjust or suspend air-bag operation. In addition to disabling air-bags when the clearance is unsafe, prior systems have slowed the rate of air-bag inflation or inflated the air-bag in stages. However, these systems may deprive shorter drivers of the full effectiveness of the air-bag system.
Other areas of concern are in the appropriate use of reduced inflation bags and in post-crash escape and rescue actions. Seat belts, automatic door locks and electric windows often become liabilities following severe impact, rollover, or in submerged vehicle situations.
However, little attention has been paid to computerized safety automation and post-crash escape as they relate to these features. Rather, industry efforts have been directed to manual devices such as the "Pointed Window Breaking Hammer" now offered as a car safety accessory to expedite escape.